Cell mediated immunity CMI to transitional cell carcinoma (TCC) is studied using a 51chromium isotope release assay. Target cells include cell lines derived from (TCC) nonmalignant urothelium and unrelated tumors. Effector cells are cryopreserved blood lymphocytes or pelvic lymph node cells. Patients with TCC are monitored for CMI at routine chemical follow-up (approximately every 3 months). The prognostic value of CMI in relation to residual tumor or recurrance after local surgery is being sought. Fresh specimens to TCC and urothelium are being established in culture to determine the frequency of cross reactive antigens in TCC, as detected by CMI.